Method and apparatus for rendering fats



Jan. 3, 1950 o Prr ET AL 2,493,459

METHOD AND APPARATUS FOR RENDERING FATS Filed March 12, 1945 I ,7 ,jJ/erafZw ,5 W E 65,

49 22 g g g Jzrzgg Patented Jan. 3, 19 56 METHOD AND APPARATUS FOR RENDERING FATS Raymond Koppit and Charles J. Davis, Jr., Chicago, Ill., assignors to Armour and Company, Chicago, 11]., a corporation of Illinois Application March 12, 1945, Serial No. 582,280

- 3 Claims.

This invention relates to method and apparatus for rendering fats and more particularly to the treatment of hog cuttings to produce lard, edible fats and other fat products.

In the treatment of hog cuttings it has heretofore been the usual practice to place the cuttings in a treating tank and to cook them by passing steam therethrough at a pressure of about 50 lb. per sq. inch for a minimum period of three to four hours. tings to lard, floaters, tankwater and tankage.

Upon completion of the cooking the steam is shut off and the cooked stock is allowed to settle into an upper stratum of lard, a next lower stratum of floaters, a next lower stratum of tankwater and a bottom stratum of tankage. The

lard is then drawn off through a pipe tapped into the tank and which lies above the lower.

level of the lard stratum, this being necessary to insure that the pipe connection will be above the floaters. To complete the lard draw-off, water is pumped into the tankwater stratum to raise the lard level to the draw-off pipe, completion of the lard draw-01f being indicated when floaters appear in the pipe.

The floaters are then drawn ofi through a pipe somewhat below the first pipe and above the bottom level of the floaters stratum. Substantially complete draw-off of the floaters is effected by pumping additional water into the tankwater stratum to bring the floaters level up to the level of the second pipe.

Thereafter the tankwater and tankage are blown off to a settling tank and resett1ed. Fat rising to the top of this mixture may be skimmed off and rendered with the floaters into edible pork fat. The remaining water is then evaporated and the tankage used in the production of liouid stick and pressed tankage or otherwise as desired.

In the practice of this method the addition of water to the tank causes a certain agitation of the material resulting in mixing. Fat remaining in the tank after draw-off of the floaters is mixed with the tankwater and tankage during blow-off thereof and is not completely recovered by skimming in the settling tank. This decreases the recovery of edible pork fat and increases the percentage of fat recovered in inedible form such as liquid stick. In addition the time required for resettling involves an ad-' ditional loss, and evaporation of the large amount of water used in the process is expensive. The present invention provides a process and This cooking reduces the cutapparatus in which these difiiculties are overcome, in which recovery and quality of edible pork fat is increased, in which both time required and amount of water employed are reduced, and which results in substantial overall savings as compared with present practices.

The invention will be better understood by reference to the accompanying drawing in which:

Figure 1 is a diagrammatic view of the apparatus illustrating the stock therein at the end of the cooking and stratifying steps; and

Figures 2, 3 and 4 are similar views illustratmg different stages in the process.

In practicing the present invention, the pork cuttings or like material to be rendered are,

placed in a vertically. elongated tank In and are cooked in the usual manner by admitting steam to the lower part of the tank through a valve pipe II. Upon completion of the cooking, the steam is shut ofl and the material in the tank is allowed to settle into an upper stratum l2 of 3 A valved lard draw-off pipe I6 is connected to i lard, a next lower stratum l3 of floaters, a next lower stratum M of tankwater and a bottom stratum l5 of tankage.

the tank and is so located that it normally lies slightly below the lard stratum and opposite the floaters stratum. A second valved draw-off pipe I I is connected to the lower part of the tank opposite the tankwater stratum.

To draw off the lard, the pipe I 6 is first opened and the material flowing therethrough is observed. Normally this material will be floaters which are collected separately to be mixed with the main body of floaters drawn off as described hereinafter. The pipe I! is then opened to draw off tankwater until lard starts to flow through the pipe l6. At this time the pipe I! is closed to hold'the bottom of the lard stratum level with the pipe, l6 and all of the lard is drawn on. It

will be noted that this operation causes substan- 7 tially no agitation of the materialso that mix- The tankwater and floaters may be withdrawn through the pipe I B but are preferably withdrawn through a separate valved pipe [9. A swinging 'nozzle 20 is connected to the pipe l9 adapted to be swung over either of two troughs 2| or 22 for collection of .tankwater and floaters respectively. The tanhwaterjlfi is first drawn off-"into the trough 2| leaving the apparatus in the condition shown in Figure 4. The floaters are then to empty the drawn 01f into the trough 22 finally tank. v 1

The tankwater may be screened to recover*sol-ids-- therefrom and after settling=maybe skimmed to recover fat therefrom. This; fat isjmixed -w-ithy the floaters and rendered as edible porlcifat."

This" material may be content of about 65%. further reduced to produce liquid stick. f'

A comparison of the conventional method as described vabove; and the :method-yof the: present: inventionmayuba readily obtainedgfrom theffole 1o,wing ;tabula-tions-of';the5actual;;results% obtained: in 1 opfllfcdiions. v underfifthe' two 1 methods;,:. In sthe e a w s onwz hieconver'ktional 5 method: herein? reported;- 1,138,3fi5spounds of; cutting fatawere renderfidr'andirrthezoperations*onuthevnewinethod 1&245Z0'8aponndsmf, rcuttingsfat awl'ere rendered? The tankwater is then evaporatedwtda solid,

mercial value than any of the other products except the lard, the increase in its yield and quality under the present method is extremely important.

ing cooking fat-containing stock in the presence of steam to produce annixture oir-lardwfloaters,

tanlzjwater andjtankage, allowingvthecooked; stoclg to'settle into strata,. withdrawingtankwatereto lower th'elard level to a;ldrawvoffipointnabove the bottom of the1stratifiied stcck withdrawing the la-rd 1 at the dIQ'WFOfifDOiIItI andTthereaft-r. separately withdrawing from the bottom of the ,g stratified stock-the tan-ka'ge; the-remaining tank;

water; and the floaters in order;

In the rendered pork fat-'the'newfmetho'd shows I a 'marked improvementzoverthe conventional method, the syield:being:aboutfl0%' greaters from about:'::10%;;less::-cuttings.:; Furthermore: it sh'as .770 :tanlcwater and tankage,-. allowing the cookedlstocki. beeng ioundvthat thisuproductphasiarbetter quality than thatproducedlby the;;co,nventional method:

n efi i n:zbe=;hand1ed -fasterandisi-su ieet to:

less. contamination' .bmmixin gwithitha tankagar.

2.. The-method-ofrrendering porksfats'comprise ingzcooking.fat-containing stoclvinnthepresence: of steamtoproducela -mixture -of-lard5 fl0a-ters;-

to settle into-strata withdrawing tanltwater talr lowersthe lardalevel to :a=draw-ofi pointabovewthe 1 bottomrof. the stratified-stock, withdrawing thee: lardlat. the-draweofipointyivithdrawingthetank-p i Since the rendered pork fat has a higher con-redo vage-from;the, .bottom -otthevstratifiedistock;and

thereafter successively withdrawing the tank- REFERENCES CITED water and the floaters from the bottom of the The following references are or record in the Stock file of this patent:

3. The method of rendering pork fats comprising placing fat containing stock in a vertically 5 UNITED S A S T TS elongated container, passing steam through the stock to cook it down into lard, floaters, tanki??? Junmelaao water and tankage, allowing the cooked stock to 247573 Mmigan Sept 27, 1881 le in Strata, tankwabel from Pewter Feb. 9 the container to lower the bottom level of the 10 705034 Cameron July 22 1902 lard stratum to a draw-01f point intermediate 1 186:510 Eldredge June 6 1916 the vertical height of the container, drawing oil! 2:269'898 Anderson Jan 13 1942 the lard from the container at the draw ofi point, and thereafter successively and separately withdrawing the tankage, the tankwater and the floatg5 ers from the bottom of the container.

RAYMOND KOPPIT. CHARLES J. DAVIS. JR. 

1. THE METHOD OF RENDERING PORK FATS COMPRISING COOKING FAT-CONTAINING STOCK IN THE PRESENCE OF STEAM TO PRODUCE A MIXTURE OF LARD, FLOATERS, TANKWATER AND TANKAGE, ALLOWING THE COOKED STOCK TO SETTLE INTO STRATA, WITHDRAWING TANKWATER TO LOWER THE LARD LEVEL TO A DRAW-OFF POINT ABOVE 